Archivos mensuales: julio 2024

In the Linux kernel, the following vulnerability has been resolved:

btrfs: qgroup: fix quota root leak after quota disable failure

If during the quota disable we fail when cleaning the quota tree or when
deleting the root from the root tree, we jump to the 'out' label without
ever dropping the reference on the quota root, resulting in a leak of the
root since fs_info->quota_root is no longer pointing to the root (we have
set it to NULL just before those steps).

Fix this by always doing a btrfs_put_root() call under the 'out' label.
This is a problem that exists since qgroups were first added in 2012 by
commit bed92eae26cc ("Btrfs: qgroup implementation and prototypes"), but
back then we missed a kfree on the quota root and free_extent_buffer()
calls on its root and commit root nodes, since back then roots were not
yet reference counted.

In the Linux kernel, the following vulnerability has been resolved:

null_blk: fix validation of block size

Block size should be between 512 and PAGE_SIZE and be a power of 2. The current
check does not validate this, so update the check.

Without this patch, null_blk would Oops due to a null pointer deref when
loaded with bs=1536 [1].

[axboe: remove unnecessary braces and != 0 check]

In the Linux kernel, the following vulnerability has been resolved:

NFSv4: Fix memory leak in nfs4_set_security_label

We leak nfs_fattr and nfs4_label every time we set a security xattr.

tgstation-server is a production scale tool for BYOND server management. Prior to 6.8.0, low permission users using the "Set .dme Path" privilege could potentially set malicious .dme files existing on the host machine to be compiled and executed. These .dme files could be uploaded via tgstation-server (requiring a separate, isolated privilege) or some other means. A server configured to execute in BYOND's trusted security level (requiring a third separate, isolated privilege OR being set by another user) could lead to this escalating into remote code execution via BYOND's shell() proc. The ability to execute this kind of attack is a known side effect of having privileged TGS users, but normally requires multiple privileges with known weaknesses. This vector is not intentional as it does not require control over the where deployment code is sourced from and _may_ not require remote write access to an instance's `Configuration` directory. This problem is fixed in versions 6.8.0 and above.

Magento-lts is a long-term support alternative to Magento Community Edition (CE). This XSS vulnerability affects the design/header/welcome, design/header/logo_src, design/header/logo_src_small, and design/header/logo_alt system configs.They are intended to enable admins to set a text in the two cases, and to define an image url for the other two cases.
But because of previously missing escaping allowed to input arbitrary html and as a consequence also arbitrary JavaScript. The problem is patched with Version 20.10.1 or higher.

In the Linux kernel, the following vulnerability has been resolved:

hfsplus: fix uninit-value in copy_name

[syzbot reported]
BUG: KMSAN: uninit-value in sized_strscpy+0xc4/0x160
sized_strscpy+0xc4/0x160
copy_name+0x2af/0x320 fs/hfsplus/xattr.c:411
hfsplus_listxattr+0x11e9/0x1a50 fs/hfsplus/xattr.c:750
vfs_listxattr fs/xattr.c:493 [inline]
listxattr+0x1f3/0x6b0 fs/xattr.c:840
path_listxattr fs/xattr.c:864 [inline]
__do_sys_listxattr fs/xattr.c:876 [inline]
__se_sys_listxattr fs/xattr.c:873 [inline]
__x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873
x64_sys_call+0x2ba0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:195
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
slab_post_alloc_hook mm/slub.c:3877 [inline]
slab_alloc_node mm/slub.c:3918 [inline]
kmalloc_trace+0x57b/0xbe0 mm/slub.c:4065
kmalloc include/linux/slab.h:628 [inline]
hfsplus_listxattr+0x4cc/0x1a50 fs/hfsplus/xattr.c:699
vfs_listxattr fs/xattr.c:493 [inline]
listxattr+0x1f3/0x6b0 fs/xattr.c:840
path_listxattr fs/xattr.c:864 [inline]
__do_sys_listxattr fs/xattr.c:876 [inline]
__se_sys_listxattr fs/xattr.c:873 [inline]
__x64_sys_listxattr+0x16b/0x2f0 fs/xattr.c:873
x64_sys_call+0x2ba0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:195
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[Fix]
When allocating memory to strbuf, initialize memory to 0.

In the Linux kernel, the following vulnerability has been resolved:

cachefiles: fix slab-use-after-free in fscache_withdraw_volume()

We got the following issue in our fault injection stress test:

==================================================================
BUG: KASAN: slab-use-after-free in fscache_withdraw_volume+0x2e1/0x370
Read of size 4 at addr ffff88810680be08 by task ondemand-04-dae/5798

CPU: 0 PID: 5798 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #565
Call Trace:
kasan_check_range+0xf6/0x1b0
fscache_withdraw_volume+0x2e1/0x370
cachefiles_withdraw_volume+0x31/0x50
cachefiles_withdraw_cache+0x3ad/0x900
cachefiles_put_unbind_pincount+0x1f6/0x250
cachefiles_daemon_release+0x13b/0x290
__fput+0x204/0xa00
task_work_run+0x139/0x230

Allocated by task 5820:
__kmalloc+0x1df/0x4b0
fscache_alloc_volume+0x70/0x600
__fscache_acquire_volume+0x1c/0x610
erofs_fscache_register_volume+0x96/0x1a0
erofs_fscache_register_fs+0x49a/0x690
erofs_fc_fill_super+0x6c0/0xcc0
vfs_get_super+0xa9/0x140
vfs_get_tree+0x8e/0x300
do_new_mount+0x28c/0x580
[…]

Freed by task 5820:
kfree+0xf1/0x2c0
fscache_put_volume.part.0+0x5cb/0x9e0
erofs_fscache_unregister_fs+0x157/0x1b0
erofs_kill_sb+0xd9/0x1c0
deactivate_locked_super+0xa3/0x100
vfs_get_super+0x105/0x140
vfs_get_tree+0x8e/0x300
do_new_mount+0x28c/0x580
[…]
==================================================================

Following is the process that triggers the issue:

mount failed | daemon exit
————————————————————
deactivate_locked_super cachefiles_daemon_release
erofs_kill_sb
erofs_fscache_unregister_fs
fscache_relinquish_volume
__fscache_relinquish_volume
fscache_put_volume(fscache_volume, fscache_volume_put_relinquish)
zero = __refcount_dec_and_test(&fscache_volume->ref, &ref);
cachefiles_put_unbind_pincount
cachefiles_daemon_unbind
cachefiles_withdraw_cache
cachefiles_withdraw_volumes
list_del_init(&volume->cache_link)
fscache_free_volume(fscache_volume)
cache->ops->free_volume
cachefiles_free_volume
list_del_init(&cachefiles_volume->cache_link);
kfree(fscache_volume)
cachefiles_withdraw_volume
fscache_withdraw_volume
fscache_volume->n_accesses
// fscache_volume UAF !!!

The fscache_volume in cache->volumes must not have been freed yet, but its
reference count may be 0. So use the new fscache_try_get_volume() helper
function try to get its reference count.

If the reference count of fscache_volume is 0, fscache_put_volume() is
freeing it, so wait for it to be removed from cache->volumes.

If its reference count is not 0, call cachefiles_withdraw_volume() with
reference count protection to avoid the above issue.

In the Linux kernel, the following vulnerability has been resolved:

cachefiles: fix slab-use-after-free in cachefiles_withdraw_cookie()

We got the following issue in our fault injection stress test:

==================================================================
BUG: KASAN: slab-use-after-free in cachefiles_withdraw_cookie+0x4d9/0x600
Read of size 8 at addr ffff888118efc000 by task kworker/u78:0/109

CPU: 13 PID: 109 Comm: kworker/u78:0 Not tainted 6.8.0-dirty #566
Call Trace:

kasan_report+0x93/0xc0
cachefiles_withdraw_cookie+0x4d9/0x600
fscache_cookie_state_machine+0x5c8/0x1230
fscache_cookie_worker+0x91/0x1c0
process_one_work+0x7fa/0x1800
[…]

Allocated by task 117:
kmalloc_trace+0x1b3/0x3c0
cachefiles_acquire_volume+0xf3/0x9c0
fscache_create_volume_work+0x97/0x150
process_one_work+0x7fa/0x1800
[…]

Freed by task 120301:
kfree+0xf1/0x2c0
cachefiles_withdraw_cache+0x3fa/0x920
cachefiles_put_unbind_pincount+0x1f6/0x250
cachefiles_daemon_release+0x13b/0x290
__fput+0x204/0xa00
task_work_run+0x139/0x230
do_exit+0x87a/0x29b0
[…]
==================================================================

Following is the process that triggers the issue:

p1 | p2
————————————————————
fscache_begin_lookup
fscache_begin_volume_access
fscache_cache_is_live(fscache_cache)
cachefiles_daemon_release
cachefiles_put_unbind_pincount
cachefiles_daemon_unbind
cachefiles_withdraw_cache
fscache_withdraw_cache
fscache_set_cache_state(cache, FSCACHE_CACHE_IS_WITHDRAWN);
cachefiles_withdraw_objects(cache)
fscache_wait_for_objects(fscache)
atomic_read(&fscache_cache->object_count) == 0
fscache_perform_lookup
cachefiles_lookup_cookie
cachefiles_alloc_object
refcount_set(&object->ref, 1);
object->volume = volume
fscache_count_object(vcookie->cache);
atomic_inc(&fscache_cache->object_count)
cachefiles_withdraw_volumes
cachefiles_withdraw_volume
fscache_withdraw_volume
__cachefiles_free_volume
kfree(cachefiles_volume)
fscache_cookie_state_machine
cachefiles_withdraw_cookie
cache = object->volume->cache;
// cachefiles_volume UAF !!!

After setting FSCACHE_CACHE_IS_WITHDRAWN, wait for all the cookie lookups
to complete first, and then wait for fscache_cache->object_count == 0 to
avoid the cookie exiting after the volume has been freed and triggering
the above issue. Therefore call fscache_withdraw_volume() before calling
cachefiles_withdraw_objects().

This way, after setting FSCACHE_CACHE_IS_WITHDRAWN, only the following two
cases will occur:
1) fscache_begin_lookup fails in fscache_begin_volume_access().
2) fscache_withdraw_volume() will ensure that fscache_count_object() has
been executed before calling fscache_wait_for_objects().

In the Linux kernel, the following vulnerability has been resolved:

firmware: cs_dsp: Use strnlen() on name fields in V1 wmfw files

Use strnlen() instead of strlen() on the algorithm and coefficient name
string arrays in V1 wmfw files.

In V1 wmfw files the name is a NUL-terminated string in a fixed-size
array. cs_dsp should protect against overrunning the array if the NUL
terminator is missing.

In the Linux kernel, the following vulnerability has been resolved:

mm: prevent derefencing NULL ptr in pfn_section_valid()

Commit 5ec8e8ea8b77 ("mm/sparsemem: fix race in accessing
memory_section->usage") changed pfn_section_valid() to add a READ_ONCE()
call around "ms->usage" to fix a race with section_deactivate() where
ms->usage can be cleared. The READ_ONCE() call, by itself, is not enough
to prevent NULL pointer dereference. We need to check its value before
dereferencing it.